The api.keyringLock should be unlocked with defer syntax

[banishee]

System info:
https://github.com/cosmos/ethermint/blob/4501bbccdc8c99532372698d4f48bc66f7de2843/rpc/namespaces/eth/api.go

Steps to reproduce:
I noticed the api code from ethermint/rpc/namespaces/eth/api.go:

func (api *PublicEthereumAPI) Accounts() ([]common.Address, error) {
	api.logger.Debug("eth_accounts")
	api.keyringLock.Lock()

	addresses := make([]common.Address, 0) // return [] instead of nil if empty

	infos, err := api.clientCtx.Keybase.List()
	if err != nil {
		return addresses, err
	}

	api.keyringLock.Unlock()

	for _, info := range infos {
		addressBytes := info.GetPubKey().Address().Bytes()
		addresses = append(addresses, common.BytesToAddress(addressBytes))
	}

	return addresses, nil
}

I suppose that this is not an appropriate way of unlocking a lock.
From my opinion, the keyringLock might not to be unlocked if the api.clientCtx.Keybase.List() cause an error
Or is there something special reason for not using defer to unlock in this function?

Additional info:
I am not sure it is a bug or not, and I just want to make it clear